The present invention pertains to improvements in sprinklers employed with sprinkler systems which are installed in structures for protection against fire, and more particularly pertains to improvements in such sprinklers which are provided with a flange or ring thereon for covering an opening in a ceiling or a sidewall in which the sprinkler is mounted.
When installing the sprinkler heads of a fire-protection sprinkler system, holes are formed in the ceiling and/or walls of a room, and each hole is centered with respect to a corresponding sprinkler head which either lies behind the opening or extends partially or entirely through it. Since these holes are unfilled, or are only partially filled by the sprinkler head, flanges and/or detachable cover plates have been used as escutcheons for covering the openings. Such flanges and/or cover plates used in combination with sprinkler heads are disclosed, for instance, in U.S. Pat. Nos. 2,389,331; 2,389,332; 2,534,066; 2,558,450; 3,198,258; 3,393,746; 3,459,266; 3,714,989 and 3,815,821. From these patents it can be seen that the flanges and/or cover plates disclosed therein for closing the openings around the sprinkler heads have little or no bracing effect with regard to supporting adjacent ceiling tile, or which prevents retraction of the sprinkler head from the opening, or else the flange is attached to the sprinkler head permanently or by means of threads, screws, nuts and bolts, coiled springs, or relatively insecure friction clasps. When the flange is permanently attached to a concealed sprinkler head, it can complicate the installation thereof, and the flange cannot be removed for inspection of the head.
Attachment of the flange to the sprinkler head by means of threads, screws, springs, and the like is costly and time consuming, and removal and reattachment of the flange for inspection of the head can be slow and cumbersome. Use of a friction clasp provides a rapid and simple means for attaching and detaching the flange, but does not provide a positive lock which prevents dislodgement of the flange as a result of vibration or shifting of the sprinkler system or the structure being protected against fire.